This clip comes from Mickey's Trailer, the 1938 Mickey Mouse cartoon, where a rapid typewriter burst was used for comic effect. The sound was later catalogued as a classic Hollywood cartoon effect, with its sharp key strokes, bell ding and carriage return becoming shorthand for frantic typing. Editors kept reusing it because it reads instantly, even at under a second long, and it still appears in memes, cartoons and short videos whenever someone wants typing to feel old-fashioned, busy and funny.